An investigation is under way into the crash of a British military plane north of Baghdad Sunday, believed to have killed 10 military personnel.

Officials in London say they are aware of reports that the C-130 aircraft may have been shot down, but say they cannot draw any conclusions until the investigation is complete. The aircraft went down on a flight between Baghdad airport and Balad airbase.

Two militant groups have separately claimed responsibility for downing the plane.

Sunday's crash is the deadliest single incident suffered by British troops since the war in Iraq began nearly two years ago.